Histoplasma capsulatum:
Phagocytosed by macrophages but are not killed
Killing of intracellular yeast depends on Th1 cell activation of ________ through release of g-IFN
By this time, organisms have spread widely in lung

macrophages

Histoplasma capsulatum:
_________ form around infected macrophages
Later they calcify (can see this on CXR)
Organisms remain viable in granulomas for years
Can be reactivated if person becomes immune suppressed

Granulomas

Histoplama:
_____% of population living in endemic areas are skin-test positive.

What fungus?
Soil organism
Found in decaying leaf litter
Found in southern and mid-western US
Infection follows inhalation of conidia

Blastomyces dermatitidis

Blastomycosis

Organism can enter blood and go to skin to form lesions
Blastomycosis

?

Diagnosis of Blastomycosis

Histopathology
See budding yeast cells
Serology

Treatment of Blastomycosis

AmphoB or an azole for more mild disease

What fungus?
Found in lower Sonoran life zone is semi arid regions of southwest US
Probably associated with burrows of desert animals
Grows rapidly following rain; drought and windy conditions spread organism large distances

Coccidioides immitis

Coccidioidomycosis

The ecological niche of C. immitis is the Sonoran desert, which includes the deserts of the _________ and northern Mexico (figure 18). It is also found in small foci in Central and South America.

Southwest (California, Arizona, New Mexico and Texas)

Pathogenesis of Coccidioidomycosis:
Inhalation of arthroconidia directly into ______

alveoli

arthroconidio

what part of Coccidioidomycosis?

Pathogenesis of Coccidioidomycosis:
arthroconidia transform into a spherule containing _______

endospores

spherule containing endospores.

Endospores can be released and travel through the body leading to extrapulmonary disease

Describe this Coccidioidomycosis picture

Coccidioidomycosis
AKA ____ fever

Valley

Diagnosis of Coccidioidomycosis

Culture of fluid from any involved site
Will grow on many media in few days
Serology- see notes page
Histopathology
See spherules

Treatment of Coccidioidomycosis

Long term treatment required with Ampho B for severe disease or an azole for mild to moderate disease

A 25-year-old man was admitted to a Colorado hospital with a 12-day history of fever, weight loss, fatigue, arthralgias, and productive cough. He had been treated by a private physician with two antibiotics during the preceding 8 days. On hospital admission, a computed tomography (CT) scan demonstrated bilateral pulmonary diffuse nodular opacities. A subsequent open lung biopsy revealed small budding yeasts. After 10 days of culture, Blastomyces dermatitidis was identified and confirmed by DNA probe (GenProbe, San Diego, California *), both at the local hospital laboratory and at CDC. The patient was treated with intravenous (IV) ___________ for 10 days, followed by a prescribed 6-month course of oral ________.

amphotericin B

itraconazole

One week later, a 35-year-old man sought care for a 15-day history of fever, fatigue, shortness of breath, arthralgias, skin lesions (punctate lesions on arms and trunk and lesions resembling erythema nodosum on legs), cough, chest pain, and weight loss. His symptoms did not improve after 9 days of treatment with two antibiotics, and he was admitted to the same hospital as patient 1. A CT scan revealed diffuse, bilateral pulmonary nodules. The consulting physician for this patient also had seen patient 1; on the basis of work history and clinical course of the disease, the consultant suspected a fungal pneumonia. Specimens obtained by transbronchial biopsy/lavage were negative for fungal elements by microscopic examination and culture. Open lung biopsy specimens revealed small budding yeasts morphologically indistinguishable from those found in patient 1. Biopsy specimens grew B. dermatitidis after 21 days of culture. The patient received IV __________ for 14 days, and at discharge, a 6-month prescribed course of oral __________.

amphotericin B

itraconazole

On March 30, 2001, CDC was notified by Pennsylvania Department of Health (PDH) of an acute respiratory febrile illness in 44 students from two colleges who traveled to Acapulco, Mexico, for spring break vacation during March 3--18. Within 7--14 days of their return from Acapulco, 21 students presented to health-care providers with illness characterized by fever, chills, dry cough, chest pain, and headache. Two students were hospitalized. On the basis of clinical symptoms and chest radiographs that revealed bilateral, nodular patchy infiltrates, acute pulmonary ____________ was the suspected illness.

histoplasmosis

The number of cases of Coccidioidomycosis in Arizona has increased in recent years
1995 reported as 14/100,000 (2X more than in previous yrs
Most of new cases were in elderly patients who developed more serious disease
Why?